Modern inventory systems, such as those in mail order warehouses, supply chain distribution centers, airport luggage systems, and custom-order manufacturing facilities, include a number of complex systems, including robots, automated shelving systems, radio frequency identification (RFID), and automated scheduling and routing equipment. Many systems, for example, comprise robots that travel to shelving systems to retrieve items, or the shelves themselves, and return them to a central location for additional processing.
Automated warehouses exist that use robots, for example, to move items or shelves from a storage location in the warehouse to a shipping location (e.g., for inventory items to be boxed and shipped). It is inevitable, however, that the paths of the robots and humans working in the warehouse will cross. Direct contact between the human workers and the robots, however, can be problematic, and a maintenance issue for the robots.